The subject matter disclosed herein relates to a method of attaching a die to a carrier, and particularly to a method of attaching a die to a carrier using a temporary attach material.
Micro-electro-mechanical system (MEMS) devices are miniaturized mechanical elements, such as sensors, actuators, and electronics. MEMS are typically fabricated using integrated circuit (IC) processes. During fabrication of the MEMS device, a die of the MEMS device is attached to a carrier or support structure. In some applications, the die is attached to the carrier using an adhesive or epoxy.
Mounting the die to the carrier tends to introduce stress on the die. The stress can be created by different rates of thermal expansion between the die and the adhesive used to attach the die to the carrier. In addition to thermal expansion, stress may also be caused by differences in other material properties such as, for example, moisture adsorption or curing time. The stress introduced to the die may cause issues, especially if a MEMS pressure sensor that depends on detecting small amount of strain is attached to a die. This is because the stress introduced to the die may cause the die to generate inaccurate pressure readings.
One approach to reduce stress introduced to a die involves using a relatively soft die attach material. However, this approach is typically only effective for devices using a relatively large die and does not usually work when a smaller die, which has dimensions that are typically less than about 1 millimeter, is employed. The soft die attach material tends to allow for too much movement of the smaller die relative to the carrier. Movement of the smaller die relative to the carrier may hinder successful wire bonding of the die to the carrier, as the smaller die tends to wobble about the soft die attach material. Therefore, it would be desirable to provide a manufacturing process that allows for a die to be attached to the carrier without introducing a significant amount of stress to the die.